Almost all aircraft have exterior lighting. Exterior aircraft light units are provided for a variety of different purposes. On the one hand, exterior aircraft light units are provided for active visibility, i.e. for the pilots and/or aircrew to view the outside environment and/or to inspect aircraft structures during flight. On the other hand, exterior aircraft light units are provided for passive visibility, with examples of such exterior aircraft light units being anti-collision light units and navigation light units. Exterior aircraft light units are subject to adverse operating conditions. In particular, exterior aircraft light units have to withstand large temperature variations. Also, many exterior aircraft light units are exposed to large aerodynamic forces and associated wear and tear, in particular due to rain, dust and snow hitting the exterior aircraft light units at high speeds. The wear and tear of the lens covers of these exterior aircraft light units leads to frequent replacements of the lens covers, with these replacements being time-consuming, costly, and resource-intensive. Also, the replacement procedures lead to lengthy down-times of the aircraft.
Accordingly, it would be beneficial to provide exterior aircraft light units that have low maintenance requirements.